Revive .dockerignore (#271)

* Revert "rm .dockerignore (#262)"

This reverts commit ffc2b86.

* add Dockerfile itself to .dockerignore

This makes changes to the Dockerfile not
to cause a full rebuild, which it does without this,
because of the COPY . /project.

Author: vorburger

.dockerignore

@@ -0,0 +1,36 @@
+# No need for the Dockerfile itself, this makes it much faster to make small changes in it
+Dockerfile
+
+# No need to push big ./.git/ into container, it's not required to build
+.git
+
+
+# Keep this in sync with .gitignore:
+
+.settings/
+.project
+.classpath
+
+bin/
+.apt_generated/
+xtend-gen/
+.rpt2_cache/
+.gradle/
+build/
+out/
+.gradletasknamecache
+/.nb-gradle/
+dist/
+
+.idea/
+*.iml
+
+node_modules/
+coverage/
+*d.ts
+
+web/.vertx/file-cache-*
+
+.vscode/
+.history/
+.vertx/